Ultrasonic endoscope

ABSTRACT

The ultrasonic endoscope includes: an insertion part that includes a tip, a base end, and a longitudinal axis; an ultrasonic transducer that is provided at the tip of the insertion part; a locking groove that is a balloon mounting portion which is disposed closer to the base end of the insertion part than the ultrasonic transducer is and on which a balloon wrapping the ultrasonic transducer is detachably mounted; a balloon pipe line that extends in the insertion part; a tip-side opening surface of the balloon pipe line that is provided closer to the tip than the locking groove and has components normal to a direction of the longitudinal axis; and a groove portion which is formed toward the tip from the tip-side opening surface as a starting point and of which at least a part overlaps the ultrasonic transducer in the direction of the longitudinal axis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of copending U.S. patent applicationSer. No. 16/569,166 filed Sep. 12, 2019, which is a Continuation of U.S.patent application Ser. No. 15/280,257 filed Sep. 29, 2016, now U.S.Pat. No. 10,459,109, issued Oct. 29, 2019, which is a Continuation ofPCT International Application No. PCT/JP2015/059184 filed on Mar. 25,2015, which claims priority under 35 U.S.C. § 119(a) to Japanese PatentApplication No. 2014-071316 filed on Mar. 31, 2014. Each of the aboveapplications is hereby expressly incorporated by reference, in theirentirety, into the present application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to an ultrasonic endoscope, and moreparticularly, to an ultrasonic endoscope where a balloon can be mountedon a tip portion of an insertion part to be inserted into a body cavity.

2. Description of the Related Art

In the related art, an ultrasonic endoscope has been used in a medicalfield. The ultrasonic endoscope includes an imaging element and aplurality of ultrasonic transducers that are integrally disposed at atip portion of an insertion part to be inserted into a body cavity of asubject. Each of the ultrasonic transducers generates ultrasonic wavestoward a portion to be observed in the body cavity and receivesultrasonic echoes (echo signals) reflected by the portion to beobserved, and electrical signals (ultrasonic wave-detection signals)corresponding to the received ultrasonic echoes are output to anultrasonic observation device (ultrasonic processor device). Then, aftervarious kinds of signal processing are performed in the ultrasonicobservation device, the electrical signals are displayed on a monitor orthe like as an ultrasonic tomographic image.

Since the ultrasonic waves and the echo signals are significantlyattenuated in the air, an ultrasonic transmission medium (for example,water, oil, or the like) needs to be interposed between the ultrasonictransducers and the portion to be observed. Thus, a stretchablebag-shaped balloon is mounted on a tip portion of the ultrasonicendoscope, and an ultrasonic transmission medium is injected into theballoon so that the balloon is inflated and is in contact with theportion to be observed. Accordingly, air is excluded from a spacebetween the ultrasonic transducers and the portion to be observed, sothat the attenuation of the ultrasonic waves and the echo signals isprevented.

A supply/discharge pipe line (supply/discharge pipe line for a balloon)is inserted into the insertion part of the ultrasonic endoscope in orderto supply and discharge an ultrasonic transmission medium into and fromthe balloon. The supply/discharge pipe line includes a supply/dischargeport (tip opening) opening to the tip portion of the insertion part, andan ultrasonic transmission medium is supplied into and discharged fromthe balloon through the supply/discharge port.

Further, the ultrasonic endoscope is cleaned and sterilized afterendoscopy, and the supply/discharge pipe line needs to be brushed.Particularly, since liquid, residue, and the like are likely to enterthe supply/discharge pipe line from the supply/discharge port in a casein which endoscopy is performed in a state in which a balloon is notmounted, brushing is necessary.

In the brushing of the supply/discharge pipe line, a cleaning brush isinserted into the supply/discharge pipe line from an operation unit sidewhere an inlet of the supply/discharge pipe line is provided, and anoperation for pushing and moving the cleaning brush toward the tip inthe supply/discharge pipe line and an operation for drawing a brushportion of the cleaning brush back toward the operation unit areperformed.

Since the supply/discharge port opens in a direction perpendicular tothe axial direction of the insertion part in the ultrasonic endoscope inthe related art, the supply/discharge pipe line provided along the axialdirection of the insertion part is connected to the supply/dischargeport in a state in which the supply/discharge pipe line is bent at aright angle or is bent obliquely. For this reason, when brushing isperformed in the supply/discharge pipe line, the brush portion disposedat the tip of the cleaning brush cannot protrude from thesupply/discharge port. Accordingly, there is a problem that liquid,residue, and the like entering the supply/discharge pipe line from thesupply/discharge port cannot be sufficiently removed. Furthermore, sincethe supply/discharge pipe line has a very small diameter ϕ of about 1.0mm and a thin cleaning brush is also used, a large bending stress isapplied to the cleaning brush at a bent portion of the supply/dischargepipe line when the bending angle of the supply/discharge pipe line isincreased. For this reason, there is a case in which the cleaning brushmay be subjected to bending damage.

In contrast, in an ultrasonic endoscope disclosed in, for example,JP2009-207758A, a tip surface is formed outside the profile of a tipunit-protruding portion where an ultrasonic observation unit is provided(unevenly thick portion side) and a supply/discharge port (a pipe lineopening) of a supply/discharge pipe line (a pipe line for a balloon) isprovided on the tip surface. According to this ultrasonic endoscope,since a brush portion of a cleaning brush may easily protrude from thesupply/discharge port, liquid, residue, and the like present near thesupply/discharge port can be efficiently removed by the cleaning brush.Further, since the pipe line for a balloon is connected to the pipe lineopening at a gentle bending angle, bending damage to the cleaning brushcan also be prevented.

SUMMARY OF THE INVENTION

However, in the ultrasonic endoscope disclosed in JP2009-207758A, inorder to ensure a space in which the supply/discharge port is disposed,the tip surface needs to be formed outside the profile of the tipunit-protruding portion where the ultrasonic observation unit isprovided (unevenly thick portion side) as described above, and the outerdiameter of the tip portion of the insertion part needs to be large. Forthis reason, it is difficult to reduce the diameter and size of the tipportion of the insertion part, which causes the physical burden on apatient to be increased. Since the tip unit-protruding portion where theultrasonic observation unit is provided needs to be made compact inorder to dispose the supply/discharge port without changing the outerdiameter of the tip portion of the insertion part, a space in which theultrasonic observation unit is provided may be caused to be notsufficient.

Further, in a structure in which the supply/discharge port is exposed tothe tip surface that is formed outside the profile of the tipunit-protruding portion, the balloon sticks on the supply/discharge portand closes the supply/discharge port when an ultrasonic transmissionmedium present in the balloon is discharged. For this reason, there isalso a problem that the ultrasonic transmission medium cannot bedischarged from the balloon.

The invention has been made in consideration of the above-mentionedcircumstances, and an object of the invention is to provide anultrasonic endoscope of which a supply/discharge pipe line can beefficiently cleaned with a cleaning brush while the diameter and size ofa tip portion of an insertion part to be inserted into a body cavity arereduced.

In order to achieve the object, an ultrasonic endoscope according to anaspect of the invention comprises: an insertion part that includes atip, a base end, and a longitudinal axis; an ultrasonic transducer thatis provided at the tip of the insertion part; a balloon mounting portionwhich is disposed closer to the base end of the insertion part than theultrasonic transducer is and on which a balloon wrapping the ultrasonictransducer is detachably mounted; a supply/discharge pipe line for aballoon that extends in the insertion part; a tip-side opening surfaceof the supply/discharge pipe line for a balloon, the tip-side openingsurface being provided closer to the tip than the balloon mountingportion and having components normal to a direction of the longitudinalaxis; and a groove portion which is formed toward the tip from thetip-side opening surface as a starting point and of which at least apart overlaps the ultrasonic transducer in the direction of thelongitudinal axis.

According to this aspect, the tip-side opening surface of thesupply/discharge pipe line for a balloon is provided closer to the tipthan the balloon mounting portion and has components in the direction ofthe longitudinal axis of the insertion part, and the groove portion,which is formed toward the tip from the tip-side opening surface as astarting point and of which at least a part overlaps the ultrasonictransducer in the direction of the longitudinal axis, is provided.Accordingly, it is possible to allow the brush portion of the cleaningbrush to protrude from the tip-side opening surface without applyingexcessive bending stress to the cleaning brush inserted into thesupply/discharge pipe line for a balloon. Therefore, it is possible toefficiently perform the brushing of the supply/discharge pipe line for aballoon while reducing the size and diameter of the tip portion of theinsertion part to be inserted into the body cavity.

In the ultrasonic endoscope according to the aspect of the invention,the groove portion includes a straight groove that extends from thetip-side opening surface in the direction of the longitudinal axis, andan inclined groove which extends from the straight groove so as to beinclined with respect to the direction of the longitudinal axis and ofwhich a depth is gradually reduced toward the tip.

In the ultrasonic endoscope according to the aspect of the invention, abase end side of the groove portion extends toward the base end beyondthe tip-side opening surface and the depth of the groove portion isreduced toward the base end.

In the ultrasonic endoscope according to the aspect of the invention,the groove portion is provided at any one of a pair of side wallportions that face each other with the ultrasonic transducer interposedtherebetween.

In the ultrasonic endoscope according to the aspect of the invention,the groove portion is provided at a bottom wall portion from which apair of side wall portions facing each other with the ultrasonictransducer interposed therebetween are erected.

In the ultrasonic endoscope according to the aspect of the invention,the groove portion extends up to a position that is closer to the baseend than a tip surface of the insertion part.

In the ultrasonic endoscope according to the aspect of the invention,the groove portion extends up to a tip surface of the insertion part.

According to the invention, it is possible to efficiently clean asupply/discharge pipe line for a balloon with a cleaning brush whilereducing the diameter and size of a tip portion of an insertion part tobe inserted into a body cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing the configuration of anultrasonography system using an ultrasonic endoscope to which theinvention is applied.

FIG. 2 is a view showing the configuration of pipe lines of theultrasonic endoscope.

FIG. 3 is a perspective view of a tip portion of an insertion part ofthe ultrasonic endoscope.

FIG. 4 is a side view of the tip portion of the insertion part of theultrasonic endoscope.

FIG. 5 is a plan view (a partial sectional view) of the tip portion ofthe insertion part of the ultrasonic endoscope.

FIG. 6 is a view showing a state in which a supply/discharge pipe lineis brushed.

FIG. 7 is a view showing another example of the structure of a grooveportion formed at a housing member.

FIG. 8 is a view showing a state in which contamination near asupply/discharge port is removed by a brush.

FIG. 9 is a view showing a structure in which a groove portion is formedon a right side wall portion of the housing member.

FIG. 10 is a view showing a structure in which a groove portion isformed on a bottom wall portion of the housing member.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An ultrasonic endoscope according to a preferred embodiment of theinvention will be described in detail below with reference to theaccompanying drawings.

FIG. 1 is a schematic view showing the configuration of anultrasonography system using an ultrasonic endoscope to which theinvention is applied.

As shown in FIG. 1 , an ultrasonography system 2 comprises an ultrasonicendoscope 10 that takes an image of the inside of a body cavity of asubject; an ultrasonic processor device 12 that generates an ultrasoundimage; an endoscopic processor device 14 that generates an endoscopicimage; a light source device 16 that supplies illumination light, whichilluminates the inside of the body cavity, to the ultrasonic endoscope10; and a monitor 18 that displays the ultrasound image and theendoscopic image.

The ultrasonic endoscope 10 includes: an insertion part 20 that is to beinserted into the body cavity of a subject; an operation unit 22 that isconnected to a base end portion of the insertion part 20 and is operatedby an operator, such as a medical doctor or a technician; and auniversal cord 24 of which one end is connected to the operation unit22. The other end portion of the universal cord 24 is provided with anultrasonic connector 26 that is connected to the ultrasonic processordevice 12, an endoscope connector 28 that is connected to the endoscopicprocessor device 14, and a light source connector 30 that is connectedto the light source device 16. The ultrasonic endoscope 10 is detachablyconnected to the ultrasonic processor device 12, the endoscopicprocessor device 14, and the light source device 16 through therespective connectors 26, 28, and 30. Further, a tube 32 for supplyingair and water and a tube 34 for suction are connected to the lightsource connector 30.

The monitor 18 receives video signals that are generated by theultrasonic processor device 12 and the endoscopic processor device 14and displays the ultrasound image and the endoscopic image. In regard tothe display of the ultrasound image and the endoscopic image, only oneof the ultrasound image and the endoscopic image can be appropriatelyswitched and displayed on the monitor 18, or both of the images can besimultaneously displayed. A monitor for displaying the ultrasound imageand a monitor for displaying the endoscopic image may be separatelyprovided.

Alternatively, the ultrasound image and the endoscopic image may bedisplayed on one monitor.

The operation unit 22 is provided with an air supply/water supply button36 and a suction button 38, which are arranged to be parallel, a pair ofangle knobs 42 and 42, and a treatment tool insertion opening (forcepsport) 44.

The insertion part 20 has a tip, a base end, and a longitudinal axis,and includes a tip portion (hard tip portion) 50, a bendable portion 52,and a soft portion 54 in this order from the tip side. The tip portion(hard tip portion) 50 is formed of a hard member. The bendable portion52 is connected to a base end side of the tip portion 50 and can bebent. The soft portion 54 connects a base end side of the bendableportion 52 to a tip side of the operation unit 22, is thin and long, andhas flexibility. The bendable portion 52 is remotely operated so as tobe bent by the rotation of the pair of angle knobs 42 and 42 of theoperation unit 22. Accordingly, the tip portion 50 can be directed in adesired direction. Further, a balloon 64 to be described below isdetachably mounted on the tip portion 50.

Here, the configuration of pipe lines of the ultrasonic endoscope 10will be described. FIG. 2 is a view showing the configuration of pipelines of the ultrasonic endoscope 10.

As shown in FIG. 2 , a treatment tool channel 100, an air supply/watersupply pipe line 102, and a balloon pipe line 104 of which one endcommunicates with the internal space of the balloon 64 are provided inthe insertion part 20 and the operation unit 22. The balloon pipe line104 is a form of a supply/discharge pipe line for a balloon of theinvention.

One end of the treatment tool channel 100 is connected to a treatmenttool outlet 94 (see FIG. 3 ) to be described below, and the other endthereof is connected to the treatment tool insertion opening 44 of theoperation unit 22. The treatment tool insertion opening 44 is closed bya cover (not shown) except when a treatment tool is to be inserted.Further, a suction pipe line 106 is branched from the treatment toolchannel 100, and the suction pipe line 106 is connected to the suctionbutton 38 of the operation unit 22.

One end of the air supply/water supply pipe line 102 is connected to anair supply/water supply nozzle 92 (see FIG. 3 ) to be described below,and the other end thereof is branched into an air supply pipe line 108and a water supply pipe line 110. The air supply pipe line 108 and thewater supply pipe line 110 are connected to the air supply/water supplybutton 36 of the operation unit 22.

One end of the balloon pipe line 104 is connected to a supply/dischargeport 70 a that is provided closer to the tip than a balloon mountingportion to be described below, and the other end thereof is branchedinto a balloon water-supply pipe line 112 and a balloon drain pipe line114. The balloon water-supply pipe line 112 is connected to the airsupply/water supply button 36, and the balloon drain pipe line 114 isconnected to the suction button 38.

One end of an air supply source pipe line 116, which communicates withan air supply pump 129, and one end of a water supply source pipe line120, which communicates with a water supply tank 118, are connected tothe air supply/water supply button 36 in addition to the air supply pipeline 108, the water supply pipe line 110, and the balloon water-supplypipe line 112. The air supply pump 129 is always operated duringultrasonic observation.

A branch pipe line 122 is branched from the air supply source pipe line116, and the branch pipe line 122 is connected to an inlet of the watersupply tank 118 (above the liquid level). Further, the other end of thewater supply source pipe line 120 is inserted into the water supply tank118 (below the liquid level). Then, when the internal pressure of thewater supply tank 118 is increased by the supply of air from the airsupply pump 129 through the branch pipe line 122, water present in thewater supply tank 118 is supplied to the water supply source pipe line120.

The air supply/water supply button 36 is a so-called two-stage switchingbutton. Although not shown, an air outlet, which communicates with theatmosphere, is formed at an operation cap 36 a of the air supply/watersupply button. When the operation cap 36 a is not operated, the airsupply/water supply button 36 allows the water supply source pipe line120 to be closed and allows the air supply source pipe line 116 tocommunicate with the air outlet of the operation cap 36 a. Accordingly,air, which is supplied from the air supply source pipe line 116, leaksfrom the air outlet of the air supply/water supply button 36. Then, whenthe air outlet is closed in this state, the air supply source pipe line116 and the air supply pipe line 108 communicate with each other in astate in which the water supply source pipe line 120 continues to beclosed. Accordingly, air is supplied to the air supply pipe line 108 andis ejected to the outside from the air supply/water supply nozzle 92.

Furthermore, when the operation cap 36 a is halfway push-operated, theair supply/water supply button 36 allows the air supply source pipe line116 to be closed and allows the water supply source pipe line 120 tocommunicate with only the water supply pipe line 110. Accordingly, watersupplied from the water supply source pipe line 120 is ejected from theair supply/water supply nozzle 92 through the water supply pipe line 110and the like. Then, when the operation cap 36 a is fully push-operated,the air supply/water supply button 36 allows the water supply sourcepipe line 120 to communicate with only the balloon water-supply pipeline 112 in a state in which the air supply source pipe line 116continues to be closed. Accordingly, water, which is supplied from thewater supply source pipe line 120, is supplied into the balloon 64through the balloon water-supply pipe line 112 and the like.

The other end of a suction source pipe line 126 of which one endcommunicates with a suction pump 124 is connected to the suction button38 in addition to the suction pipe line 106 and the balloon drain pipeline 114. The suction pump 124 is also always operated during ultrasonicobservation. The suction button 38 is a two-stage switching button likethe air supply/water supply button 36.

When an operation cap 38 a of the suction button 38 is not operated, thesuction button 38 allows the suction source pipe line 126 to communicatewith the outside (the atmosphere). The reason for this is that a loadapplied to the suction pump 124 is increased unless the suction sourcepipe line 126 communicates with the atmosphere since the suction pump124 is always operated. When the suction source pipe line 126 is allowedto communicate with the atmosphere, an increase of the load of thesuction pump 124 is suppressed.

Further, when the operation cap 38 a is halfway push-operated, thesuction button 38 allows the suction source pipe line 126 to communicatewith only the suction pipe line 106. Accordingly, a negativepressure-suction force of the suction pipe line 106 and the treatmenttool channel 100 is increased, and various materials to be sucked aresucked from the treatment tool outlet 94 (see FIG. 3 ). Then, when theoperation cap 38 a is fully push-operated, the suction button 38 allowsthe suction source pipe line 126 to communicate with only the balloondrain pipe line 114. Accordingly, a negative pressure-suction force inthe balloon drain pipe line 114 and the balloon pipe line 104 isincreased, and water present in the balloon 64 is drained.

Next, the structure of the tip portion 50 of the ultrasonic endoscope 10will be described in detail. FIG. 3 is a perspective view of the tipportion 50, FIG. 4 is a side view of the tip portion 50, and FIG. 5 is aplan view (a partial sectional view) of the tip portion 50.

As shown in FIGS. 3 to 5 , an ultrasonic observation unit 60 thatacquires an ultrasound image and the endoscopic observation unit 80 thatacquires an endoscopic image are provided at the tip portion 50 of theultrasonic endoscope 10.

The ultrasonic observation unit 60 comprises an ultrasonic transducer 62that includes a plurality of ultrasonic vibrators. The respectiveultrasonic vibrators of the ultrasonic transducer 62 are arranged atregular intervals in the shape of a convex curve along the axialdirection of the tip portion 50 (a direction of the longitudinal axis ofthe insertion part 20), and are adapted to be sequentially driven on thebasis of drive signals that are input from the ultrasonic processordevice 12. Accordingly, convex electronic scanning is performed over ascanning range shown in FIG. 4 by W. When the respective ultrasonicvibrators are driven, the ultrasonic vibrators sequentially generateultrasonic waves toward a portion to be observed, receive ultrasonicechoes (echo signals) reflected by the portion to be observed, andoutput electrical signals (ultrasonic wave-detection signals), whichcorrespond to the received ultrasonic echoes, to the ultrasonicprocessor device 12. Then, after various kinds of signal processing areperformed in the ultrasonic processor device 12, the electrical signalsare displayed on the monitor 18 as the ultrasound image.

A bag-shaped balloon 64, which covers and wraps the ultrasonictransducer 62, is mounted on the tip portion 50 in order to prevent theattenuation of the ultrasonic waves and the ultrasonic echoes (echosignals) (see FIGS. 4 and 5 ). The balloon 64 is made of a stretchableelastic material, and a stretchable locking ring 66 is formed at an openend of the balloon 64. A locking groove 68, which forms a balloonmounting portion, is provided at the tip portion 50. The locking groove68 is formed of an annular groove portion that is formed over the entirecircumference (outer periphery) of the tip portion 50 in acircumferential direction having a center on the axis. The locking ring66 is fitted to the locking groove 68, so that the balloon 64 isdetachably mounted on the tip portion 50.

The balloon 64 is inserted into the body cavity in a state in which theballoon 64 contracts so as to come into close contact with the outerwall surface of the tip portion 50. Then, when an operator generatesultrasonic waves toward the portion to be observed from the respectiveultrasonic vibrators of the ultrasonic transducer 62, the operatorsupplies water, which is present in the water supply tank 118, into theballoon 64 through the balloon pipe line 104, the balloon water-supplypipe line 112, and the like by fully push-operating the operation cap 36a of the air supply/water supply button 36 and inflates the balloon 64until the balloon 64 comes into contact with the inner wall of the bodycavity. Accordingly, since a space between the portion to be observedand the ultrasonic transducer 62 is filled with water that is anultrasonic transmission medium, the balloon 64 improves the adhesivenessof the tip portion 50 to the inner wall of the body cavity and preventsthe ultrasonic waves, which are generated from the respective ultrasonicvibrators of the ultrasonic transducer 62, and the ultrasonic echoesfrom being attenuated by air. Further, when an operator draws theinsertion part 20 to the outside from the body cavity, the operatordischarges water, which is present in the balloon 64, through theballoon pipe line 104, the balloon drain pipe line 114, and the like byfully push-operating the operation cap 38 a of the suction button 38 andallows the balloon 64 to contract so that the balloon 64 comes intoclose contact with the outer wall surface of the tip portion 50 as whenthe operator inserts the insertion part 20 into the body cavity. Forexample, latex rubber is used for the balloon 64. Further, it ispreferable that the ultrasonic transmission medium supplied into theballoon 64 is deaerated water from which dissolved gas has been removed.

The balloon pipe line 104 as the supply/discharge pipe line for aballoon extends in the insertion part 20 as described above, and atip-side opening surface 70, which has components normal to thedirection of the longitudinal axis of the insertion part 20 (the axialdirection of the tip portion 50), is provided at the tip of the balloonpipe line 104. The tip-side opening surface 70 is provided closer to thetip than the locking groove 68 that forms the balloon mounting portion,and includes a supply/discharge port 70 a that is opened at one end(tip) of the balloon pipe line 104.

A housing member (exterior member) 72, which holds the ultrasonictransducer 62, is provided with a groove portion 74 (having a notchedshape) that is formed by notching a part of the outer wall of thehousing member. The groove portion 74 is formed toward the tip from thetip-side opening surface 70 as a starting point, and is formed so thatat least a part of the groove portion 74 overlaps the ultrasonictransducer 62 in the direction of the longitudinal axis of the insertionpart 20.

A structure in which the groove portion 74 is provided at a left sidewall portion 72 a of a pair of side wall portions 72 a and 72 b, whichface each other with the ultrasonic transducer 62 interposedtherebetween, of an outer wall portion of the housing member 72 when thetip portion 50 is viewed from the tip side has been described in theembodiment shown in FIGS. 3 to 5 . However, the invention is not limitedthereto, and the groove portion 74 may be provided at a right side wallportion 72 b or a bottom wall portion 72 c from which these side wallportions 72 a and 72 b are erected, as described below.

Here, the structure of the groove portion 74 will be described in moredetail. The groove portion 74, which is formed toward the tip from thetip-side opening surface 70 as a starting point, extends to the nearside (the base end side) of a tip surface of the tip portion 50 as shownin FIG. 5 . The groove portion 74 includes a straight groove 74 a and aninclined groove 74 b in this order from the base end side (a side wherethe tip-side opening surface 70 is formed).

The straight groove 74 a extends from the tip-side opening surface 70 inthe direction of the longitudinal axis of the insertion part 20, andincludes a bottom surface parallel to the direction of the longitudinalaxis of the insertion part 20. The straight groove 74 a does not bend abrush portion, which is provided at the tip of a cleaning brush led outfrom the supply/discharge port 70 a of the tip-side opening surface 70,and guides the brush portion in the axial direction of the balloon pipeline 104. It is preferable that the length L (see FIG. 5 ) of thestraight groove 74 a is 1 mm or more, and the length L is 1.5 mm in thisembodiment. If the length L is set to this length, it is possible toallow the brush portion of the cleaning brush to protrude from thesupply/discharge port 70 a without applying excessive stress to thebrush portion of the cleaning brush.

The inclined groove 74 b extends from the straight groove 74 a so as tobe inclined with respect to the direction of the longitudinal axis ofthe insertion part 20, and the depth of the groove is gradually reducedtoward the tip. That is, the inclined groove 74 b includes a bottomsurface that is formed so as to be inclined with respect to the normaldirection of the tip-side opening surface 70 (the opening direction ofthe supply/discharge port 70 a). Accordingly, when the brush portion ofthe cleaning brush, which protrudes from the supply/discharge port 70 a,is further pushed and moved toward the tip, the brush portion of thecleaning brush is guided in a direction in which the brush portion isseparated from the ultrasonic transducer 62 and is in a state in whichthe brush portion is drawn to the outside (the lateral side) from theouter wall surface of the housing member 72. Therefore, the brushportion of the cleaning brush can be easily washed with a hand. When aninclination angle α (see FIG. 5 ) of the inclined groove 74 b is toolarge, excessive stress is applied to the brush portion of the cleaningbrush. Accordingly, it is preferable that the inclination angle α is atleast 45° or less, and the inclination angle α is 10° in thisembodiment.

Particularly, in this embodiment, the groove portion 74 (having anotched shape) is formed by notching a part of the outer wall of thehousing member 72 arranged to be parallel to the ultrasonic transducer62, that is, the groove portion 74 is formed so that at least a part ofthe groove portion 74 overlaps the ultrasonic transducer 62 in thedirection of the longitudinal axis of the insertion part 20.Accordingly, it is possible to sufficiently ensure the length of thegroove portion 74 (the length of the groove portion 74 in the directionof the longitudinal axis of the insertion part 20) without increasingthe size of the tip portion 50 in the axial direction, and to make theinclination angle α of the inclined groove 74 b be gentler. Therefore,since excessive stress is not applied to the brush portion of thecleaning brush that is guided to the lateral side of the housing member72 by the inclined groove 74 b, it is possible to prevent a bendingdamage to cleaning brush.

The endoscopic observation unit 80 includes an observation portion 82and an illumination portion 84, and the observation portion 82 and theillumination portion 84 are disposed on an inclined surface portion 86that is formed on the tip portion 50 toward the base end from thelocking groove 68 so as to be inclined with respect to the axialdirection of the tip portion 50.

The observation portion 82 includes an observation window 88; and anobjective lens of an observation optical system, and an imaging element,such as a Charge Coupled Device (CCD) or a Complementary Metal OxideSemiconductor (CMOS), which is disposed at an image formation positionof the objective lens, are provided in the rear of the observationwindow 88. A signal cable (not shown) is connected to a board thatsupports the imaging element. The signal cable is inserted into theinsertion part 20 and the universal cord 24, extends up to the endoscopeconnector 28, and is connected to the endoscopic processor device 14. Anobservation image, which is received from the observation window 88, isformed on the light-receiving surface of the imaging element and isconverted to an electrical signal (an imaging signal), and theelectrical signal is output to the endoscopic processor device 14through the signal cable and is converted to a video signal. Then, thevideo signal is output to the monitor 18 connected to the endoscopicprocessor device 14, so that an endoscopic image is displayed on ascreen of the monitor 18.

The illumination portion 84 includes illumination windows 90 and 90, anda light-emitting end of a light guide 128 (see FIG. 2 ) is disposed inthe rear of the illumination windows 90 and 90. The light guide 128 isinserted into the insertion part 20 and the universal cord 24 and anincident end of the light guide 128 is disposed in the light sourceconnector 30. Accordingly, the light source connector 30 is connected tothe light source device 16, so that illumination light emitted from thelight source device 16 is transmitted to the illumination windows 90 and90 through the light guide and is emitted forward from the illuminationwindows 90 and 90.

The air supply/water supply nozzle 92 is provided near the observationwindow 88 on the inclined surface portion 86 of the tip portion 50 inaddition to the observation window 88 and the illumination windows 90and 90. The air supply/water supply nozzle 92 ejects water or air toremove foreign materials and the like adhered to the surface of theobservation window 88.

Further, the tip portion 50 is provided with a treatment tool outlet 94.The treatment tool outlet 94 is connected to the treatment tool channel100 (see FIG. 2 ) inserted into the insertion part 20, and a treatmenttool, which is inserted into the treatment tool insertion opening 44, isintroduced into the body cavity from the treatment tool outlet 94through the treatment tool channel 100. The treatment tool outlet 94 ispositioned closer to the base end than the locking groove 68, but may beprovided close to the ultrasonic transducer 62 so that the movement ofthe treatment tool introduced into the body cavity from the treatmenttool outlet 94 can be confirmed by an ultrasound image.

An elevator 96 for making the lead-out direction of the treatment tool,which is introduced into the body cavity from the treatment tool outlet94, be variable is provided in the treatment tool outlet 94. A wire (notshown) is mounted on the elevator 96, and the elevating angle of theelevator 96 is changed by a pushing/drawing operation that is performedby the operation of an elevating lever (not shown) of the operation unit22. Accordingly, the treatment tool is led out in a desired direction.

In the ultrasonic endoscope 10 having the above-mentioned structure, thebrushing of the balloon pipe line 104 is performed as follows after theend of endoscopy. FIG. 6 is a view showing a state in which the balloonpipe line 104 is brushed by using the cleaning brush. As shown in FIG. 6, a cleaning brush 130 includes a brush insertion part 132 and a brushportion 134 that is disposed at the tip portion of the brush insertionpart 132.

First, after the balloon 64 is removed from the tip portion 50 of theinsertion part 20, the cleaning brush 130 is inserted from the suctionbutton 38 side that is an inlet of the balloon pipe line 104. Then,while the cleaning brush 130 inserted into the balloon drain pipe line114 of the balloon pipe line 104 is moved forward and backward, thecleaning brush 130 is pushed and moved toward the tip and the brushportion 134 of the cleaning brush 130 is allowed to protrude from thesupply/discharge port 70 a that is an outlet of the balloon pipe line104. The cleaning brush 130 may be inserted from the air supply/watersupply button 36 side.

Then, when the brush portion 134 of the cleaning brush 130 is furtherpushed and moved, the brush portion 134 of the cleaning brush 130 isoffset in a direction in which the brush portion 134 is separated fromthe axis of the tip portion 50 by the inclined groove 74 b after thebrush portion 134 of the cleaning brush 130 is guided in the samedirection as the direction of the longitudinal axis of the insertionpart 20 (that is, the axial direction of the balloon pipe line 104) bythe straight groove 74 a.

In this case, since the groove portion 74 (having a notched shape) isformed by notching a part of the outer wall of the housing member 72arranged to be parallel to the ultrasonic transducer 62 in thisembodiment as described above, it is possible to sufficiently ensure thelength of the groove portion 74 (the length of the groove portion 74 inthe axial direction of the tip portion 50) without increasing the sizeof the tip portion 50 and to make the inclination angle α (see FIG. 5 )of the inclined groove 74 b be gentler. For this reason, since excessivestress is not applied to the brush portion 134, it is possible toprevent a bending damage to the cleaning brush 130. Accordingly, it ispossible to easily draw the brush portion 134 of the cleaning brush 130to the lateral side of the tip portion 50. Therefore, the brush portion134 can be easily washed with a hand.

Further, when the brush portion 134 of the cleaning brush 130 is washedwith a hand, a user determines the degree of contamination of the brushportion 134. In a case in which it is determined that the brushing ofthe balloon pipe line 104 is further needed, the user removes thecleaning brush 130 from the suction button 38 side, washes the brushportion 134 with a hand again, and determines the degree ofcontamination of the brush portion 134 after the user performs thebrushing of the balloon pipe line 104 while performing an operation fordrawing the cleaning brush 130 back. Then, in a case in which it isdetermined that the brushing of the balloon pipe line 104 is furtherneeded, the user inserts the cleaning brush 130 from the suction button38 side and repeatedly performs the same processing as described above.

In a case in which the brushing of the balloon pipe line 104 isperformed as described above and a fact that the balloon pipe line 104is in a clean state is determined from the degree of contamination ofthe brush portion 134 of the cleaning brush 130, the brushing ends.

As described above, according to this embodiment, the tip-side openingsurface 70 of the balloon pipe line 104, which forms thesupply/discharge pipe line for a balloon, is provided closer to the tipthan the locking groove 68 that is the balloon mounting portion,includes components in the direction of the longitudinal axis of theinsertion part 20, and is provided with the groove portion 74, which isformed toward the tip from the tip-side opening surface 70 as a startingpoint and of which at least a part overlaps the ultrasonic transducer 62in the direction of the longitudinal axis. Accordingly, it is possibleto provide the groove portion 74 without increasing the size of the tipportion 50 in the direction of the longitudinal axis of the insertionpart 20, and to sufficiently ensure the length of the groove portion 74.Therefore, since it is possible to allow the brush portion of thecleaning brush to protrude from the supply/discharge port 70 a withoutapplying excessive bending stress to the cleaning brush inserted intothe balloon pipe line 104, it is possible to easily remove liquid,residue, and the like adhered to the vicinity of the supply/dischargeport 70 a. As a result, it is possible to efficiently perform thebrushing of the balloon pipe line 104 while reducing the size anddiameter of the tip portion 50 of the insertion part 20.

In this embodiment, as shown in FIGS. 3 to 5 , the groove portion 74 isformed at a position, which is closer to the base end than the tipsurface 50 a of the tip portion 50, so as to converge. However, theinvention is not limited thereto, and the groove portion 74 may beformed so as to extend up to the tip surface 50 a of the tip portion 50as shown in, for example, FIG. 7 . According to a structure thatincludes a groove portion 74 opened to the tip surface 50 a, since thelength of the groove portion 74 is longer than that of the structureshown in FIGS. 3 to 5 , it is possible to make the inclination angle α(see FIG. 5 ) of the inclined groove 74 b be gentler. Accordingly, it ispossible to more effectively prevent a bending damage to the cleaningbrush. It is preferable that the inclination angle α of the inclinedgroove 74 b is in the range of 5° to 10°, and the inclination angle α ofthe inclined groove 74 b is set to, for example, 7.5°.

Further, since the groove portion 74 is opened to the tip surface 50 aof the tip portion 50, an effect of allowing the balloon 64 to reliablycontract is also obtained even if the balloon 64 sticks on the sidesurface of the tip portion 50 when an ultrasonic transmission mediumpresent in the balloon 64 is discharged.

According to the structure in which the groove portion 74 is formed at aposition closer to the base end than the tip surface 50 a of the tipportion 50 so as to converge as shown in FIGS. 3 to 5 , it is possibleto smoothly machine the tip surface 50 a of the tip portion 50.Accordingly, it is possible to improve the insertability of theinsertion part 20 of the ultrasonic endoscope 10 into the body cavity.

Furthermore, it is preferable that the base end side of the grooveportion 74 extends toward the base end beyond the tip-side openingsurface and the depth of the groove is reduced toward the base end asshown in FIG. 8 enlarging the vicinity of the supply/discharge port 70 ain FIG. 5 . It is preferable that an inclination angle β of a baseend-side inclined surface 98 of the groove portion 74 (the inclinationangle of the base end-side inclined surface 98 with respect to adirection perpendicular to the direction of the longitudinal axis of theinsertion part 20) is in the range of 10° to 45°, and the inclinationangle β is, for example, 30°. If the groove portion 74 has a shapeextending outward toward the base end in this way, it is possible toeasily scrape off contaminations that are present near thesupply/discharge port 70 a when the groove portion 74 is brushed with abrush 99 for a groove portion.

Moreover, the structure in which the groove portion 74 is provided atthe left side wall portion 72 a of the pair of side wall portions 72 aand 72 b, which face each other with the ultrasonic transducer 62interposed therebetween, of the outer wall portion of the housing member72 when the tip portion 50 is viewed from the tip side has beendescribed in this embodiment as shown in FIGS. 3 to 5 . However, thegroove portion 74 may be provided at another outer wall portion that isarranged to be parallel to the ultrasonic transducer 62. For example, asshown in FIG. 9 , the groove portion 74 may be provided at the rightside wall portion 72 b when the tip portion 50 is viewed from the tipside. Further, as shown in FIG. 10 , the groove portion 74 may beprovided at a bottom wall portion 72 c from which the left and rightside wall portions 72 a and 72 b are erected.

According to the structure that comprises the groove portion 74 (havinga notched shape) formed by notching a part of the outer wall of thehousing member arranged to be parallel to the ultrasonic transducer 62in this way, it is possible to reduce the size and diameter of the tipportion 50 without increasing the outer diameter of the tip portion 50.Particularly, since the groove portion 74 is formed so that at least apart of the groove portion 74 overlaps the ultrasonic transducer 62 inthe direction of the longitudinal axis of the insertion part 20, it ispossible to significantly reduce the size of the tip portion 50 in thedirection of the longitudinal axis of the insertion part 20 incomparison with a structure in which the groove portion 74 does notoverlap the ultrasonic transducer 62.

As shown in FIGS. 3 to 5 , the housing member 72 where the grooveportion 74 and the supply/discharge port 70 a are formed does not needto be formed of a single member and may be formed of a plurality ofmembers. For example, the housing member 72 may include a tip-sidehousing member that holds the ultrasonic transducer 62 and a baseend-side housing member that is connected to the locking groove 68, anda base end side of the groove portion 74 and the supply/discharge port70 a may be formed at the base end-side housing member.

The ultrasonic endoscope according to the invention has been describedin detail above, but the invention is not limited to the above-mentionedembodiment. It goes without saying that the invention may have variousimprovements and modifications without departing from the scope of theinvention.

EXPLANATION OF REFERENCES

-   -   10: ultrasonic endoscope    -   12: ultrasonic processor device    -   14: endoscopic processor device    -   16: light source device    -   18: monitor    -   20: insertion part    -   22: operation unit    -   24: universal cord    -   50: tip portion    -   52: bendable portion    -   54: soft portion    -   44: treatment tool insertion opening    -   60: ultrasonic observation unit    -   62: ultrasonic transducer    -   64: balloon    -   68: locking groove    -   70: tip-side opening surface    -   70 a: supply/discharge port    -   72: housing member    -   74: groove portion    -   80: endoscopic observation unit    -   82: observation portion    -   84: illumination portion    -   86: inclined surface portion    -   88: observation window    -   92: air supply/water supply nozzle    -   94: treatment tool outlet    -   96: elevator    -   104: balloon pipe line

What is claimed is:
 1. An ultrasonic endoscope comprising: an insertionpart that including a tip, a base end, and a longitudinal axis; anultrasonic transducer provided at the tip of the insertion part; aballoon mounting portion which is disposed closer to the base end of theinsertion part than the ultrasonic transducer is and on which a balloonwrapping the ultrasonic transducer is detachably mounted; a balloon pipeline extending in the insertion part; a tip-side opening configured tocommunicate with the balloon pipe line; and a tip-side opening surfaceon which the tip-side opening is provided and which has componentsnormal to a direction of the longitudinal axis, wherein at least onesurface of a holder configured to hold the ultrasonic transducer is on aline extending from the tip-side opening along the direction of thelongitudinal axis.
 2. The ultrasonic endoscope according to claim 1,wherein the at least one surface of the holder forms a space between thetip-side opening surface and the balloon, in a state where the balloonis mounted on the balloon mounting portion.
 3. The ultrasonic endoscopeaccording to claim 1, wherein the at least one surface of the holder isat least one of a pair of side wall portions that face each other withthe ultrasonic transducer interposed therebetween.